Mystery Surrounding Chinese Supernova Solved by NASA

7 February, 2012 at 09:15 | Posted in Science | Leave a comment
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By Cassie Ryan & Stephanie Lam
Epoch Times Staff

Join The Epoch Times in celebrating the Chinese New Year with this article on a modern analysis of the Chinese ancients’ observation of a supernova 2,000 years ago!

An ancient celestial event observed by Chinese astronomers almost two millennia ago has been explained using NASA’s Spitzer Space Telescope and Wide-field Infrared Survey Explorer WISE.

Scientists in the 1960s identified the phenomenon as the first supernova recorded in history, but its spherical remains are much bigger than expected.

The remnants of the explosion are known as RCW 86, and are located about 8,000 light-years away. The supernova occurred in a hollowed-out cavity, emitting matter much further and faster than normal.

“This supernova remnant got really big, really fast,” said lead researcher Brian J. Williams at North Carolina State University in a press release.

“It’s two to three times bigger than we would expect for a supernova that was witnessed exploding nearly 2,000 years ago. Now, we’ve been able to finally pinpoint the cause.”

The explosion was described as a “guest star” by the Chinese in 185 A.D. According to the Book of the Later Han, written in 445 A.D., the supernova was spotted in October (in the Chinese calendar) of that year, and remained until June of the following year.

The guest star is said to have had five colors, and fortune tellers saw it as an omen of war. Later, it was thought to be associated with a war that broke out in 189 A.D., causing thousands of deaths.

The new study, published online in the Astrophysical Journal, shows that it is a Type Ia supernova generated by the death of a white dwarf star.

Read more: Mystery Surrounding Chinese Supernova Solved by NASA | Space & Astronomy | Science | Epoch Times

Mental Stimulation Might Cut Dementia Risk

7 February, 2012 at 06:28 | Posted in Body & Mind | 1 Comment
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Keeping sharp could reduce brain protein linked to Alzheimer’s

VOA News

People who engage in mentally stimulating activities over a lifetime have lower levels of a protein in the brain associated with Alzheimer’s disease, a new study finds.

That supports other research which suggests reading, writing, and playing games may lower the risk of dementia.

Researchers worked with a group of 65 older-adult volunteers with no symptoms of Alzheimer’s disease.

The more cognitively active you can be over the course of your lifespan, the better.
— Susan Landau, research scientist

They answered questions about how often they engaged in stimulating mental activities throughout their lifetimes.

They also got positron emission tomography (PET) brain scans which can identify beta-amyloid deposits. Those deposits are found in the brains of people who have Alzheimer’s.

University of California–Berkeley research scientist Susan Landau says the study showed a link between the quantity of deposits and the lifetime level of brain stimulation.

“People who were the most cognitively active throughout their life, they had the least amyloid in their brains,” she says.

“Based on this association between greater cognitive activity and less amyloid, we think that these people will go on to have a reduced risk of Alzheimer’s disease.”

Keep in mind that the people in this study, many of them in their 70s and 80s, did not show any symptoms of Alzheimer’s. Scientists are still trying to understand the connection between beta-amyloid deposits in the brain and dementia.

Aging and a family history of Alzheimer’s are both considered risk factors, but those are factors we can’t control.

And even if your brain hasn’t been particularly active up until now, Landau says it’s not too late to start ratcheting up your mental activities.

“I think that cognitive stimulation is probably beneficial at any age. But, what our findings from this study show, is that the more cognitively active you can be over the course of your lifespan, the better.”

Read more: Mental Stimulation Might Cut Dementia Risk | Western Medicine | Health | Epoch Times

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